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PATENTED MAR. l, 1904.

L. M. EBIGSSON, JACK FIELD FOR TELEPHONES.

APPLICATION FILED JUNE 18 1902.

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UNITED STATES Patented March 1, 1904.

PATENT OFFICE.

LARS MAGNUS ERIGSSON, OF STOCKHOLM, SWEDEN, ASSIGNOR TO AKTIE- BOLAGET L. M. ERICSSON & 00., OF STOCKHOLM, SWEDEN.

JACK-FIELD FOR TELEPHONES.

SPECIFICATION forming part of Letters Patent N0. 753,562, dated. March 1, 1904.

Application filed June 18, 1902.

To all whom, it may concern:

Be it known that I, LARs MAGNUS ERICSSON, a subject of the King of Sweden and Norway, and a resident of Thulegatan 5, Stockholm, in the Kingdom of Sweden, have invented certain new and useful Improvements in J aok-Fields for Telephones, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention relates to jack-fields for telephones. 1

The invention includes the construction, combination, and arrangement of parts hereinafter described, and particularly brought out in the claim.

The invention is illustrated in the accompanying drawings, in which Figure 1 is a front view of a jack strip pushed into two grooves in the standards; and Fig. 2 is a plan view of the jack-strip, the standards being shown in section.

1 is a plate carrying the several parts of the jack-stripand provided with holes 2.

4 4 are thimbles or testrings pressed into a front strip 3, of ebonite, screwed onto the plate 1. A tailpiece 5, also screwed onto the plate 1, carries the jack-springs 6. The plate projects with its ends beyond the endsof the tailpiece 5, and cut into the standards 7 are the slots or grooves 8.

The strip is pushed with the ends of the plate into the slots or grooves until the lateral edges 9 of the forepiece makes contact with the front edges of the standards. The forepiece is provided at its ends with notches 10 of a shape such that when two strips are placed in position side by side the abutting notches 10 together form grooves adapted to receive strips of fiber or other suitable material. The strips are secured in position by screws 12 Serial No. 112,140. (No model.)

passing through notches 13 in the forepieces ,of the jack-strips and screwed into the standards. Such a strip 11 can suitably extend over five rows of jack-strips located one above the other and serves to keep the said jackstrips in position. It is obvious that by the described arrangement a reliable guidingand supporting of the jack-strip at both ends is obtained, so that the strips cannot press upon one another and so that they can be easily removed and placed in position.

In the drawings the strip is shown supported along the whole length of its lateral edges; but I wish it to be understood that it is often suflicient to provide slots or grooves at two or more parts of the lateral edges,depending upon the cross-section of the standards. If, for instance, the standards are I-shaped in cross-section, slots or grooves are provided in the projecting flanges, so that the strip will be supported at two points of each lateral edge.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

A jack-field comprising standards having grooves, a sheet-metal plate having its edges or parts thereof extending into the grooves in the standards, pieces of insulating material mounted upon the said sheet-metal plate in such a manner as to be totally carried by the witnesses.

LARS MAGNUS ERICSSON. Witnesses: v ERNST SvAN VIs'r, AUG. SoRENsEN. 

